1. Field of the Invention
The present invention relates to a cover structure that restrains rainwater or the like from entering into a plug hole provided to a cylinder head of an engine.
2. Description of the Related Art
Conventionally, it is known that a plug cap which is to be attached to a plug hole provided to a cylinder head cover has a rain cover and the rain cover restrains rainwater or the like from entering into the plug hole. Specifically, at the opening of the plug hole, the rain cover is fit to a projection portion provided at an outer circumferential edge of the opening of the plug hole. This restrains rainwater or the like from entering the plug hole. JP 8-335488 A is a prior art document.
Thus, in order to restrain rainwater or the like from entering the plug hole, it is necessary to form the plug cap such that the rain cover is located at the opening of the plug hole and also form a projection portion at an outer circumferential edge of the opening of the plug hole, in a state where the plug cap is attached to the plug hole.
However, the depth of the plug hole varies in each model and it is necessary to prepare plug caps having a rain cover which is set according to the depth of the plug hole of each model. Thus, number of different types of plug caps increases. Further, since it is necessary to form a projection portion at the outer circumferential edge of the opening of the plug hole, manufacturing a cylinder head cover is not easy. In other words, according to the conventional cover structure of the plug hole, since the number of types of plug caps increases and manufacturing the cylinder head cover is not easy, the cost of the cover structure of the plug hole increases.